For 1990-2009 cars only
- Measure the engine oil level. Fill, as required.
- Using the scan tool, inspect for diagnostic codes within the engine control module (ECM). Refer to Diagnostic System Check - Vehicle . Repair, as required.
- Verify proper engine oil pressure and operation of the active fuel management oil pressure relief valve. Refer to Oil Pressure Diagnosis and Testing .
- Inspect the CMP actuator solenoid valve for proper operation. Refer to Camshaft Position Actuator Solenoid Valve Inspection .
- Verify proper operation of the CMP actuator control system. Refer to Diagnostic Starting Point - Engine Controls .
Important: Camshaft Position (CMP) Actuator and Solenoid Valve Diagnosis and Testing is applicable for RPO LY6/L76/L92.
| • | If valve inspection confirms proper movement of the spool, replace the CMP actuator and CMP valve. |
| • | If valve inspection confirms improper movement of the spool, replace only the CMP valve. |
